Hund's Rule states that; Every orbital in a sub-shell is singly occupied with one electron before any one orbital is doubly occupied, and all electrons in singly occupied orbitals have the same spin (to maximize total spin)
- The justification for this rule is to tell how the electrons in an atom should be placed into degenerate orbitals.
- It is also used to determine the ground state of an atom or molecule.
- Can also fairly predict the lowest state of a given excitation electronic configuration.
- Hund's rule therefore corrects the problem that would be experienced by Aufbau Principle when it comes to the different 2p orbitals , regarding the order of filling the orbitals with electrons.